Abstract: Electrochemical sensors and biosensors belong to the efficient tools for research of biopolymers, including nucleic acids and proteins, as well as bioactive, genotoxic and pharmacologically active substances which interact with the biopolymers and influence their structure and function. This project continues in successful collaboration between applicant´s and co-applicant´s laboratories. We propose to study behavior of natural and chemically modified nucleic acids at electrodes surfaces of different materials, particularly amalgams and various carbon-based materials. We will study redox, adsorption-desorption and catalytic processes of biopolymers and coupled electroactive groups, formation self-assembled layers of thiol-terminated oligonucleotides, interactions of DNA immobilized at the electrodes surfaces with small molecules and proteins, and influence of DNA structure on its interactions with electrodes surfaces. Development of new techniques for the detection of DNA damage, its chemical modification and interactions will be a part o the project.